<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <!-- MD5加密工具类 -->
  <script src = "https://cdn.bootcss.com/blueimp-md5/2.10.0/js/md5.min.js">

  </script>
</head>
<body>

<!--
    表达绑定提交事件
    οnsubmit= 绑定一个提交检测的函数，true;false
    将这个结果返回给表单，使用onsubmit接收
    οnsubmit接受的是带return的东西
-->
<form action="http://guozhivip.com/" method="post" onsubmit="return aaa()">
  <p>
    <span>用户名：</span>
    <input type="text" id="username" name="username"/>
  </p>
  <p>
    <span>密码：</span>
    <input type="password" id="password" />
  </p>
  <input type="hidden" id="md5-password" name="password">

  <!--绑定事件,onclick被点击-->
  <button type="submit" >提交</button>

</form>

<script>
  function aaa(){
    alert(1);
    var username = document.getElementById("username");
    var pwd = document.getElementById("password");
    // console.log(uname.value);
    // console.log(pwd.value);
    var md5pwd = document.getElementById("md5-password");
    // MD5 算法
    // pwd.value = md5(pwd,value);
    md5pwd.value = mad5(pwd.value);
    // console.log(pwd.value);
    // 可以校验判断表单内容，true就是通过提交，false就是阻止提交
    return false;
  }
</script>

</body>
</html>